The translational inhibitor and amnestic agent emetine also suppresses ongoing hippocampal neural activity similarly to other blockers of protein synthesis.

The consolidation of memory is thought to ultimately depend on the synthesis of new proteins, since translational inhibitors such as anisomycin and cycloheximide adversely affect the permanence of long-term memory. However, when applied directly in brain, these agents also profoundly suppress neural activity to an extent that is directly correlated to the degree of protein synthesis inhibition caused. Given that neural activity itself is likely to help mediate consolidation, this finding is a serious criticism of the strict de novo protein hypothesis of memory. Here, we test the neurophysiological effects of another translational inhibitor, emetine. Unilateral intra-hippocampal infusion of emetine suppressed ongoing local field and multiunit activity at ipsilateral sites as compared to the contralateral hippocampus in a fashion that was positively correlated to the degree of protein synthesis inhibition as confirmed by autoradiography. This suppression of activity was also specific to the circumscribed brain region in which protein synthesis inhibition took place. These experiments provide further evidence that ongoing protein synthesis is necessary and fundamental for neural function and suggest that the disruption of memory observed in behavioral experiments using translational inhibitors may be due, in large part, to neural suppression.

Tailor-made recombinant prokaryotic lectins for characterisation of glycoproteins.

Development of biosimilars is costly, where glycan analysis is a significant constraint on time and money. This paper provides an in-depth characterisation of several novel recombinant prokaryotic lectins (RPLs), developed through directed evolution, displaying specific binding activities to α-mannose, ß-galactose, fucose and sialic acid residues, tested against major biosimilar targets. The binding characterisation of all lectins was performed employing the principles of bio-layer interferometry (BLI), with help of the streptavidin-coated sensor with the biotinylated lectins. The binding activity of the RPLs and the specificity to a broad range of glycoproteins and glycoconjugates were evaluated and compared to those of equivalent plant-derived lectins. While exhibiting better or similar specificity, RPLs displayed significantly better binding in all cases. The binding mechanisms are explained with particular focus on the role hydrogen bonding plays in the change of specificity for a galactose specific lectin. Furthermore, different sets of RPLs and their plant equivalents were assayed against the different glycoprotein targets to evaluate the analytical parameters of the lectin-glycoprotein interaction. The obtained LoDs reached by the RPLs were lower than those of their plant counterparts apart from one, exhibiting RPL:PL LoD ratios of 0.8, 2.5, 14.2 and 380 for the sets of lectins specific to fucose, α-mannose, ß-galactose and sialic acid, respectively. Such enhancement in analytical parameters of RPLs shows their applicability in protein purification and as bioanalytical tools for glycan analysis and biosensor development.

Respuesta a la carta «Asuntos fundamentales en la formación de nuevos especialistas en radiodiagnóstico» / Reply to the letter "Fundamental topics in the training of new diagnostic imaging specialists"

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El papel del residente en su formación y en la actividad docente del servicio de radiodiagnóstico / The resident's role in training and teaching in diagnostic imaging departments

La nueva ley de especialidades española ha corregido las limitaciones de la anterior sobre el tutor y sus funciones. Sin embargo sigue careciendo de una descripción del papel del residente en su formación. El Estatuto del Residente y el Programa de la Especialidad aportan más información sobre este aspecto. La normativa establece que el residente no es un objeto pasivo en su formación. Además de sus obligaciones laborales que incluyen la exclusividad laboral y el conocimiento y cumplimiento de los reglamentos y normas de funcionamiento de las instituciones en que está integrado, el residente tiene el deber de formarse e ir adquiriendo progresivamente responsabilidades relativas a la especialidad. Esto incluye también una parte de formación no asistencial, preparación de sesiones, asistencia a comités, dominio de las nuevas tecnologías y la capacidad del residente de apoyarse en recursos on-line. Por otra parte, según el Estatuto del Residente este es un miembro del servicio a todos los efectos, compartiendo los fines de éste y de la institución, estando obligado a ayudar al cumplimiento de sus objetivos. Y también a cumplir los objetivos de su programa de formación y a tener una actitud activa en el aprendizaje. El residente es tan responsable del resultado final de su formación como los especialistas del servicio en que se forma (AU)

New Spanish Law of Medical Specialties has come to correct the limitations of previous regulations regarding the figure and the functions of the Tutor. However, it continues lacking a description of the role of the residents in their training. Resident's Statute and Specialty Program add some information. Regulations establish that the residents are not passive actors in their training. As well as their labor obligations, including exclusivity and observance of the rules of the institutions in which they are working, the residents have the obligation of train theirselves and of progressively taking on responsibilities relatives to the specialty. This includes non-assistential training also, medical sessions preparation, attendance to committees and use of new technologies and on-line resources. Moreover, following Resident's Statute, the residents are full member of the Radiology department, sharing its goals and those of the institution in which it is included, and helping in its achievement. And they are committed also to achieve the goals of their training program and to have an active attitude in the training process. A resident is as important to the result of the training process as the members of the staff (AU)

[The resident's role in training and teaching in diagnostic imaging departments]. / El papel del residente en su formación y en la actividad docente del servicio de radiodiagnóstico.

New Spanish Law of Medical Specialties has come to correct the limitations of previous regulations regarding the figure and the functions of the Tutor. However, it continues lacking a description of the role of the residents in their training. Resident's Statute and Specialty Program add some information. Regulations establish that the residents are not passive actors in their training. As well as their labor obligations, including exclusivity and observance of the rules of the institutions in which they are working, the residents have the obligation of training themselves and of progressively taking on responsibilities relative to the specialty. This includes non-assistential training also, medical sessions preparation, attendance to committees and use of new technologies and on-line resources. Moreover, following Resident's Statute, the residents are full members of the Radiology department, sharing its goals and those of the institution in which it is included, and helping in its achievement. And they are committed also to achieve the goals of their training program and to have an active attitude in the training process. A resident is as important to the result of the training process as the members of the staff.

Fretting corrosion behaviour of ball-and-socket joint on dental implants with different prosthodontic alloys.

The fretting corrosion of five materials for implant suprastructures (cast-titanium, machined-titanium, gold alloy, silver-palladium alloy and chromium-nickel alloy), was investigated in vitro, the materials being galvanically coupled to a titanium ball-and-socket-joint with tetrafluoroethylene under mechanical load. Various electrochemical parameters (E(corr), i(corr), Evans diagrams, polarization resistance and Tafel slopes) were analyzed. The microstructure of the different dental materials was observed before and after corrosion processes by optical and electron microscopy. It can be observed that the mechanical load produces an important decrease of the corrosion resistance. The cast and machined titanium had the most passive current density at a given potential and chromium-nickel alloy had the most active critical current density values. The high gold content alloys have excellent resistance corrosion, although this decreases when the gold content is lower in the alloy. The palladium alloy had a low critical current density due to the presence of gallium in this composition but a selective dissolution of copper-rich phases was observed through energy dispersive X-ray analysis.

Enhanced wear resistance of ball-and-socket joints of dental implants by means of titanium gaseous nitriding.

The aim of this research is the surface hardening of the ball-and-socket joint of dental implants by means of heat treatments in order to obtain titanium nitrides. These nitrides minimize the wear of the titanium used in prosthesis. In this paper the optimum heat treatment, the hardness and the wear resistance are described in relation to the ball-and-socket joint without heat treatment.

Growth of bioactive surfaces on dental implants.

Some metallic materials, such as pure titanium, Ti-6Al-4V, are used for dental and orthopedic implants under load-bearing conditions. However, they do not form a chemical bond with bone, which would achieve a good implant-bone fixation in service. In recent works, it has been demonstrated that an in vitro, chemically deposited, bone-like apatite layer with bone-bonding ability could be induced on a titanium surface. By reproducing that chemical procedure, in this work, a dense bone-like apatite layer was formed on the surface of the titanium in simulated body fluid. In addition, the different steps and kinetics of the layer-formation have been studied, because the observation of the samples in the wet state by means of the environmental scanning electron microscope has allowed the observation in situ of the apatite deposition process over a number of days. One of the most important features of the present study is that it can be carried out on a single titanium sample and the process is not interrupted at any stage. One of the main drawbacks of this chemical method is that the samples covered with apatite are susceptible to contamination by bacteria. The behavior of different types of antibiotics used to avoid this contamination has also been studied using the environmental scanning electron microscope. Finally, osteoblast cells have been cultured on the apatite-coated titanium samples to assess their biocompatibility.

Fracture and fatigue behavior of shot-blasted titanium dental implants.

This investigation studies the effect of the shot-blasting treatment on the cyclic deformation behavior of a commercially pure titanium, with two microstructures: equiaxed and acicular. The fatigue tests were carried out in artificial saliva medium at 37 degrees C. Cyclic deformation tests have been carried out up to fracture, and the fatigue crack nucleation and propagation have been analyzed. The results show that the shot-blasting treatment improves the fatigue life in the microstructures studied, and that the equiaxed was better in mechanical properties than the acicular. The cause of this improvement in the mechanical properties is due to the compressive stress on the material surface for the shot-blasted specimens. Hardness tests were carried out to determine the value of these internal stresses.

Automation of a spectrophotometric method for measuring L -carnitine in human blood serum.

A spectrometric method for the determination of L-carnitine has been developed based on the reaction of the 5,5' dithiobis-(2-nitrobenzoic) acid (DTNB) and adapted to a Technicon RA-2000 automatic analyser Química Farmacéutica Bayer, S.A.). The detection limit of the method is 13.2 mumol/l, with a measurement interval ranging from 30 to 320 mumoll1. Imprecision and accuracy are good even at levels close to the detection limit (coeffcient of variation of 5.4% for within-run imprecision for a concentration of 35 mumol/l). A good correlation was observed between the method studied and the radiometric method. The method evaluated has suffcient analytical sensitivity to diagnose carnitine deficiencies. The short time period required for sample processing (30 samples in 40min), the simple methodology and apparatus, the ease of personnel training and the low cost of the reagents make this method a good alternative to the classical radiometric method for evaluating serum L-carnitine in clinical laboratories without radioactive installations.